1. Field of the Invention
A non-toxic hypocompatible biodegradable germicide effective against a wide range of pathogenic organisms.
2. Description of the Prior Art
Modern health care facilities are confronted with complex medical problems, whether in a practioner's office, clinic or large hospital. Such facilities must care for persons with life-threatening diseases while protecting other patients in the same facility from becoming infected. Thus, controlling viral and microbial contamination is a critically important task facing health care facilities today.
In the past, the health care industry believed that sanitation and disinfection applied primarily only to emergency rooms and operating rooms or suites. However, today health care provides an awareness that chemical sanitation and disinfection is necessary in virtually every area of the modern treatment facility.
This awareness has been heightened by the rapid increases in the spread of deadly communicable diseases such as the AIDS virus (HIV), hepatitis and tuberculosis, which has dramatically increased public awareness for the need of an effective protective means.
The need for such protective means applies equally to contaminated surfaces not only to health care facilities but to such environs as public restrooms, telephones, tables and other surfaces contacted by the public as well as for topical application directly on a patient's skin.
Various spray germicides for sanitizing such surfaces is typified by in U.S. Pat. No. 3,445,564. U.S. Pat. No. 3,445,564 is directed to a method, compositions and articles for sanitizing public or communal facilities prior to individual use. The method consists of applying a thin layer of a rapidly drying liquid germicidal composition to a surface such as a toilet seat. The rapidly drying germicidal compositions consist essentially of a lower aliphatic alcohol and at least about 5 percent of a volatizing agent therefor, such as acetone. Isopropyl alcohol has excellent germicidal activity and is sufficiently volatile to give a satisfactory drying rate when blended with suitable proportions of a volatilizing agent. Inasmuch as the lower aliphatic alcohols are not sufficiently volatile to afford usefully short drying times for practical purposes in the method and articles of the Kirschner invention it was necessary to include a volatilizing agent in the germicidal composition.
The proportion of volatizing agent to lower aliphatic alcohol in the rapidly drying germicidal compositions employed in the invention may vary widely depending upon a number of factors, which include among others, the volatility of the alcohol employed, the volatility of the volatilizing agent, the desired drying rate of the germicidal composition, the amount of germicidal agent applied to the surface to be treated and the method of application of the germicide, not to mention the prevailing conditions of temperature and relative humidity under which the product is to be employed.
Although the isopropyl alcohol-acetone composition of U.S. Pat. No. 3,445,564 has germicidal activity against bacteria, fungi and other lower organisms, additional antibacterial, antifungal or other active ingredients may be incorporated to enhance the overall germicidal effectiveness. Suitable germicidal additives include the well known antibacterial quaternary ammonium compound. In essence, U.S. Pat. No. 3,445,564 teaches the use of isopropyl alcohol to kill a limited number of germs on a dry toilet seat with the addition of acetone to volatize an already highly volatile chemical to rapidly dry the toilet seat for use within 30 seconds.
The use of a dye in a bactericidal solution as disclosed in U.S. Pat. No. 2,449,274 is employed to provide a visual indication of the effectiveness of such sprays.
U.S. Pat. No. 4,678,658 shows an aerosol spray for use in disinfecting a surface for personal use such as a public restroom facility or telephone. The composition and delivery of the compositions provides for the placement of a spray of disinfectant which includes a dye that disappears as the spray effects the germicidal activity of the disinfectant. The composition is also rapidly drying, so that the dye disappears as well as the disinfecting composition leaving the surface dry. However, the spray is corrosive and environmentally unsafe.
U.S. Pat. No. 3,821,413 discloses a formulation of materials which permits an effective, uniform rate of evaporation of glycols from an air circulator device to reduce airborne bacteria in the surrounding atmosphere. It was observed that the relative amounts and identities of the components of the invention are critical to the attainment of the desired continuous evaporation of glycols over a prolonged period of time.
The composition of U.S. Pat. No. 3,821,413 is a single phase liquid composition especially adapted for volatilization at a substantially uniform rate from the air circulator device. Generally speaking, the composition includes three essential components (1) a glycol, (2) an organic polar coupling compound for maintaining the homogeneity prevents the glycol from separating from the mixture during evaporation of the mixture into the atmosphere and (3) an organic, relatively non-polar compound for forming hydrophobic micelles with the glycol molecules in the resulting mixture for reducing the affinity of the glycol to atmospheric moisture and thereby increasing the rate at which the glycol may be evaporated into the atmosphere.
The composition contains the glycol germicide. If desired, other suitable germicides or antiseptic agents can be added provided, however, that the glycol concentration of the composition does not fall below 5 percent by weight of the total mixture. Such germicides include quaternary ammonium compounds, phanols, bisphenols, salicylanilides,carbanilides, formaldehyde and chloride.
The required glycol evaporation rate for attaining the desired air sanitizing performance depends on the satisfactory stability and uniform nature of the liquid composition during evaporation from the mixture. Accordingly, the compositions of the invention include from about 2 percent to about 40 percent by weight of an organic polar coupling compound for maintaining the homogeneity of the mixture to prevent the glycol from separating from the mixture during the evaporation process.
The affinity of glycols to attract atmospheric moisture significantly reduces their volatility and impairs their evaporation rate. Accordingly, the compositions of the invention include from about 5 percent to about 80 percent by weight of an organic, relatively non-polar compound for forming hydrophobic micelles surrounding the glycol molecules in the mixture for reducing the affinity of the glycol to atmospheric moisture and thereby increase the rate of evaporation of the glycol. Without this micelle formation, it was found that the glycol or mixture of glycols in the mixture cannot evaporate appreciably in an air circulator device containing a wick immersed in the liquid composition.
U.S. Pat. No. 3,806,593 is directed to an acne treatment medication applied to the skin for preventing the formation of acne or decreasing already established acne. An important factor for the occurrence of ache is the presence of bacteria in the sebaceous glands in the skin. It is known that the bacteria in the sebaceous glands form esterases which hydrolyze the sebum fats to alcohols and free fatty acids.
The medicinal acne-preventing or acne-diminishing composition of U.S. Pat. No. 3,806,593 is based on the bacterial esterase activity in the sebaceous glands which together with the water already present in the skin can hydrolyze an ester having a good penetration capacity into the sebaceous glands to form one and preferably two antibacterially active components, viz. an acid and an alcohol, which are harmless to the skin. The active compound in the composition is one or more esters chosen from the group consisting of ethyl lactate, isopropyl lactate and/or glycerol mono or dilactate. The esters hydrolyze in the sebaceous glands due to the esterases present in the glands to form the corresponding acids and alcohols. Lactic acid and the lower alcohols and also glycerol to a certain extent exert a good antibacterial activity when formed in situ in the sebaceous glands. The esters are lipophilic and can thus penetrate into the said glands. Even if a beneficial action can be achieved by application of the ester or esters per se it has been found to be suitable to apply the ester in the form of a solution in ethyl alcohol or isopropyl alcohol. The alcohol prevents hydrolysis of the ester already in the composition. the alcohol moves the hydrolysis equilibrium towards ester formation. The alcohol can also facilitate the penetration of the ester into the skin.
As is well-known alcohol in high concentrations may cause a drying-out of the skin. To counteract this effect, the composition may include a moisture-retaining agent such as a lower, suitably water-free polyol, viz. propylene glycol or glycerol. The content of propylene glycol or glycerol in the composition according to the invention may be up to 25 percent, suitably not more than 10 percent by weight and preferably 1-5 percent. High levels of polyol tend to make the composition smeary upon application on the skin and should thus be avoided.
The preferred composition according to the invention consists of about 15 percent by weight of ethyl lactate, about 2 percent by weight of propylene glycol, the remainder being ethyl alcohol.
In summary, U.S. Pat. No. 3,806,593 relates to acne medication comprising esters that hydrolize in the sebaceous glands in combination with an alcohol to prevent hydrolysis of the esters as well facilitate the penetration of the ester into the skin, and propylene glycol or glycerol to prevent drying of the skin. The preferred ratio of the constituents is 15 percent to 83 percent to 2 percent respectively.
U.S. Pat. No. 4,664,909 discloses a stable, fast drying pituitous powder deodorant suspension in an alcohol media containing a minimal amount of water and a critical amount of the essential hydroxyethyl cellulose as the suspending agent.
The fast drying pituitous suspension of particulate material in an aqueous alcohol media contains hydroxyethyl cellulose at levels above its normal solubility limit by polyhydric alcohol.
More specifically, U.S. Pat. No. 4,664,909 relates to stable pituitous suspensions of particulate material, preferably about 1-20 percent, uniformly suspended in alcohol/aqueous media containing a high alcohol content and a lower water content. The alcohol media may be a lower monohydric alcohol selected from the group consisting of methanol, ethanol, isopropanol and mixtures thereof. The use of polyhydric alcohols such as propylene glycol, butylene glycol and polyols thereof, and glycerin decreases the critical water level required in the hydroxyethyl cellulose-containing alcohol media.
It has been unexpectedly found that powders can be suspended in alcoholic/aqueous media containing a high alcohol content and a lower water content by using the water soluble polymer hydroxyethyl cellulose at critical levels above its ethanol solubility range which may be broadened by specified polyhydric alcohols. This polymer is unique in its property to form stable suspensions.
Specifically, polyhydric alcohols can be partially substituted for the monohydric alcohol, not to exceed the monohydric alcohol content. The monohydric alcohol content, such as ethanol, must exceed the upper solubility level for the water soluble polymer hydroxyethyl cellulose in ethanol or other lower alkanol. The reported upper solubility level of this water soluble polymer in ethanol is 70 percent. Below this level and within normal soluble use ranges, a uniformly viscous liquid is obtained which pours evenly. Although, it appears aesthetically desirable, it will not support suspended powder and segregation occurs. However, at ethanol concentrations above its solubility range, the polymer becomes less soluble and forms the desired pititious type liquid. If ethanol is further increased resulting in very low water levels the polymer will precipitate out and its suspending properties are again lost. Accordingly, a 70:30 ratio of ethanol-water is optimum. However, it was found that this problem can be eliminated by the sufficient addition of a polyhydric alcohol such as glycerine, propylene glycol, butylene glycol and polyglycols thereto.
Accordingly, it has been found that the monohydric alcohol constitutes about 55-85 percent; and the water content may be as low as 5 percent if at least 10 percent polyhydric alcohol is also present in the suspension. The combined water and polyhydric alcohol content is at least 15 percent and may be up to about 25 percent. Thus, it is apparent that the proportions of monohydric alcohol, water and polyhydric alcohol are interdependent.
In summary, U.S. Pat. No. 4,664,909 teaches a fast-drying deodorant comprising a critical amount of hydroxyethyl cellose as the deodorant to encapsulate or isolate bacteria to prevent growth of the bacteria, suspended in a solution of monohydric alcohol to provide the fast drying characteristics and polyhydric alcohol to improve the overall soluability of the solution to allow the use of increased levels of monohydric alcohol. The relative proportions of the monohydric alcohol, water and polyhydric alcohol are driven or determined by the desired solubility and therefore are interdependent.
U.S. Pat. No. 3,966,902 disclosed various polymer complex carriers such as propylene glycol for use with an active ingredient such as a disinfectant or fragrance.
U.S. Pat. No. 4,690,779 refers to the use of propylene glycol in combination with alcohol and fragrances. This composition is both toxic and non-biodegradable.
U.S. Pat. No. 4,209,500 teaches a composition suitable for use in aerosol sprays including an anhydrous alcohol and fragrance or perfume. This composition is corrosive, non-biodegradable and non-evaporative.
Additional examples of the prior art are found in U.S. Pat. No. 580,213, 4,282,179, 4,265,899, 4,283,421, 4,364,515, 4,550,105, 4,105,431, 4,243,403, 4,278,206, 4,322,475, 4,436,732, 4,597,887, 4,252,694, 4,279,762, 4,325,201, 4,540,505 and 4,675,397.
Examination of the prior art reveals that most existing disinfectants are either toxic or non-biodegradable or both. Toxic chemicals that are not biodegradable contaminate the environment, the soil and the water supply. Recent federal, state and local regulations are designed to reduce or eliminate such environmental contamination resulting from the use of such disinfectants.
In recognition of the dangers of existing disinfectants, health facilities are required to notify employees that toxic chemicals are in use and inform them of the possible hazards that result or could result as a consequence of misuse or spills. Such notices must also be given to the community at large.
Other laws and regulations require users to document the use of toxic chemicals and require that the excess, waste and residue be collected and properly stored. These materials must be collected by licensed and approved toxic waste companies, taken to authorized disposal sites and legally destroyed. The cost of disposing of such toxic material is often more expensive than the initial purchase price.
Simply stated, the prior art fails to teach or suggest an effective non-toxic biodegradable surface active disinfectant/antiseptic for application on contaminated surfaces or for safe use on a patient's skin.
Disinfectants today should be non-toxic as well as biodegradable, capable of killing or inactivating pathogenic organisms. Further, such disinfectants should be chemically compatible with the numerous different surfaces found in modern healthcare facilities.
As described more fully hereinafter the instant invention is directed to an environmentally safe germicide capable of killing anaerobic and aerobic bacteria, viruses including the HIV virus, mildew, mold and fungus. The principal active anti-microbial, anti-viral ingredients of the instant invention are selected from a group of monohydric alcohols and polyhydric alcohols.
In the past such alcohols have had limited use outside the laboratory due to various undesirable characteristics of alcohol. For example, it has been universally accepted that alcohol has very limited application as a widely used disinfectant because alcohol is unable to penetrate protein rich material, evaporates quickly, has limited stability and shelf life, has a pungent odor, tends to form a glaze on hard surfaces possibly hiding or covering visible contamination and dries the skin.
The instant invention has involved an extensive development program involving the unexpected formulation of certain chemicals to reduce or inhibit those undesirable features of alcohol and to make alcohol safe and effective for use outside the laboratory.